In step 3 of the citric acid cycle, the oxidation of isocitrate and the production of CO₂ are coupled to the reduction of NAD⁺, generating NADH and an α-ketoglutarate molecule.In the isocitrate molecule shown in Figure 13-32, which carbon is lost as CO₂ and which is converted to a carbonyl carbon? Figure 13-32

Question

Quizplus · Accepted Answer

In the isocitrate molecule shown in Figure 13-32, the carbon at position 6 is lost as CO2 and the carbon at position 4 is converted into a carbonyl carbon during the oxidation of isocitrate in step 3 of the citric acid cycle. Therefore, the correct answer is choice D, which includes both 6 and 4.

In Step 3 of the Citric Acid Cycle, the Oxidation